Mayor Marion Barry's year-long search for a new house appears to be almost over. Barry now is negotiating to buy a four-bedroom, red-brick colonial home at 3607 Suitland Rd. SE, in the solidly middle-class Fairfax Village section near the edge of the city.

Barry did not make the announcement. Neither did Marcita B. Hinton, an aide to City Council member Nadine P. Winter (D-Ward 6), who owns the house. The announcement was made yesterday by one of Barry's frequent political foes, Council member Willie J. Hardy (D-ward 7), who would be the mayor's Council representative if he decides to buy the home.

Neither Barry nor Hinton would disclose the price of the house, but homes in the area generally sell for more than $100,000.

Barry has been seeking a house ever since he was elected mayor last fall. He now rents a reconditioned row house on Capitol Hill. During the past several months, Barry has concentrated his search in the far southeast area in an effort to help build a base in an area that the mayor's advisers feel is increasing in political importance.

The Barry family, the mayor and wife Effi, had looked at several other homes, but rejected most of them, including some they had made offers on, as too little for too much.

Yesterday, Barry refused to comment on the house.